Bad breath is one of the more common clinical symptoms and many patients suffer from bad breath. To check bad breath, a simpler and more objective way is to get a few close people to smell it. But there are many patients in the clinic who do not want to use this method and want to apply their own examination to check bad breath. There are some ways to do this. First of all, the first one can wash our wrist, lick it with our tongue on the inside of our wrist, wait for some time and smell if there is a significant odor in that area. The second, you can cover our mouth and nose with our hands and exhale a large mouthful of gas. Then smell whether there is a distinct odor in our exhaled gas. Of course these two cases, if for some rhinitis or cold patients may be less sensitive. Then also through the observation method, we can look at our tongue and gums through the mirror. Most people have a healthy tongue that is pink with some tongue papillae structures on it, but if the tongue is noticeably yellow or white, it mostly means that the patient has bad breath.